City's major spill preceded by a smaller one; long-term fixes eyed

The East Burlington Wastewater Treatment Plant, top left, adjacent to the Haw River at the spill site.

Sam Roberts / Times-News

By Molly McGowan / Times-News

Published: Tuesday, February 4, 2014 at 03:13 PM.

A line break leading to the worst waste spill in Burlington’s history was preceded by a much smaller leak three days before.

Michael Layne, field operations manager in city water resources department, Monday night gave the City Council an update on the Jan. 27 spill into the Haw River. He said staff members have been in constant contact with the N.C. Department of Environment and Natural Resources since the leak was detected, and that it may be time to look at reinforcing or replacing some of the city’s sewer system.

Layne gave the timeline of events leading up to the 3.5 million gallons of untreated wastewater dumping into the river from a break in the East Burlington Wastewater Treatment Plant’s force main, including the smaller leak that took place just three days prior.

A break had occurred in the same force main line Jan. 24, but only 25,000 gallons emptied into the Haw River since crews were able to divert the sewage flow into the treatment plant’s “equalization basin,” Layne said. That break was repaired over the weekend.

“And then we had this second break,” Layne said.

Since Monday’s break occurred in the pressurized line that pumps sewage from the inflow pump station up to the treatment process area — over a 70-foot elevation difference — the wastewater flooded back down to where it came from, Layne said.

To save the pumps that were being flooded, they were shut off — which meant the sewer backed up along the sewer line that runs along the Haw River, called the Haw River Interceptor line. The sewage was pushed up and out of the manholes that dot that line, and into the Haw River.

“This is disturbing that they’re getting this many pipe breakage(s) … all in a short period of time,” said Elaine Chiosso, executive director of and spokeswoman for the Haw River Assembly. “This is not an uncommon problem” with sewage structures in the United States, she said. “It’s these aging systems.

“I’m hoping the city and the state are looking at the system for other weaknesses,” Chiosso said.

BURLINGTONIS looking at replacing a stretch of the Haw River Interceptor and reinforcing the force main on the wastewater treatment plant that broke in two places.

The Haw River Interceptor is a 42-inch corrugated metal pipe that runs along the river from Graham-Hopedale Road to the wastewater treatment plant, and transports 4 million to 5 million gallons of sewage daily, Layne said.

As of the 1960s, he said, corrugated metal pipe was prohibited from being installed in sanitary sewer systems.

“One of the things we’re going to have to try to address in the future is this is … a ’59 vintage pipe, so it’s 65 years old,” Layne said.

He and Water Resources Director Bob Patterson said the department is looking at replacing 3,500 feet of the Haw River Interceptor at the wastewater treatment plant end of the line.

Regarding the force main on the plant site, Layne said that in in most cases, such pipes are laid on top of a bed of gravel, which creates a sort of cushion.

“This one is laid directly on granite rock,” he said.

“We’re going to look and see if we can line the force main on the plant property,” Patterson said.

He explained the structural lining process, which consists of inserting a long, sock-like material into the pipe, using heat or pressure to expand the “sock” to the inside dimensions of the pipe, then allowing it to harden.

“That’s probably the most likely option,” Patterson said.

An alternative would be installing a second force main line at the plant.

“That would be a more expensive option,” he said.

Patterson also told the council that it would make sense to tackle both projects at the same time since a bypass pump and line would have to be installed for the Haw River Interceptor line replacement, which could be utilized while crews repair the force main on plant property.

“We’re getting together a bid package and estimates,” Layne said.

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A line break leading to the worst waste spill in Burlington’s history was preceded by a much smaller leak three days before.

Michael Layne, field operations manager in city water resources department, Monday night gave the City Council an update on the Jan. 27 spill into the Haw River. He said staff members have been in constant contact with the N.C. Department of Environment and Natural Resources since the leak was detected, and that it may be time to look at reinforcing or replacing some of the city’s sewer system.

Layne gave the timeline of events leading up to the 3.5 million gallons of untreated wastewater dumping into the river from a break in the East Burlington Wastewater Treatment Plant’s force main, including the smaller leak that took place just three days prior.

A break had occurred in the same force main line Jan. 24, but only 25,000 gallons emptied into the Haw River since crews were able to divert the sewage flow into the treatment plant’s “equalization basin,” Layne said. That break was repaired over the weekend.

“And then we had this second break,” Layne said.

Since Monday’s break occurred in the pressurized line that pumps sewage from the inflow pump station up to the treatment process area — over a 70-foot elevation difference — the wastewater flooded back down to where it came from, Layne said.

To save the pumps that were being flooded, they were shut off — which meant the sewer backed up along the sewer line that runs along the Haw River, called the Haw River Interceptor line. The sewage was pushed up and out of the manholes that dot that line, and into the Haw River.

“This is disturbing that they’re getting this many pipe breakage(s) … all in a short period of time,” said Elaine Chiosso, executive director of and spokeswoman for the Haw River Assembly. “This is not an uncommon problem” with sewage structures in the United States, she said. “It’s these aging systems.

“I’m hoping the city and the state are looking at the system for other weaknesses,” Chiosso said.

BURLINGTONIS looking at replacing a stretch of the Haw River Interceptor and reinforcing the force main on the wastewater treatment plant that broke in two places.

The Haw River Interceptor is a 42-inch corrugated metal pipe that runs along the river from Graham-Hopedale Road to the wastewater treatment plant, and transports 4 million to 5 million gallons of sewage daily, Layne said.

As of the 1960s, he said, corrugated metal pipe was prohibited from being installed in sanitary sewer systems.

“One of the things we’re going to have to try to address in the future is this is … a ’59 vintage pipe, so it’s 65 years old,” Layne said.

He and Water Resources Director Bob Patterson said the department is looking at replacing 3,500 feet of the Haw River Interceptor at the wastewater treatment plant end of the line.

Regarding the force main on the plant site, Layne said that in in most cases, such pipes are laid on top of a bed of gravel, which creates a sort of cushion.

“This one is laid directly on granite rock,” he said.

“We’re going to look and see if we can line the force main on the plant property,” Patterson said.

He explained the structural lining process, which consists of inserting a long, sock-like material into the pipe, using heat or pressure to expand the “sock” to the inside dimensions of the pipe, then allowing it to harden.

“That’s probably the most likely option,” Patterson said.

An alternative would be installing a second force main line at the plant.

“That would be a more expensive option,” he said.

Patterson also told the council that it would make sense to tackle both projects at the same time since a bypass pump and line would have to be installed for the Haw River Interceptor line replacement, which could be utilized while crews repair the force main on plant property.